NANO

106

ENGINE 273 MPFI

• Thrust Clearance:

Using a thickness measure gauge, measure the

clearance as shown in fig. If the limit is exceeded,

replace the camshaft or camshaft bearing caps.

CAMSHAFT THRUSTCLEARANCE

STANDARDVALUE

LIMIT

0.1 to 0.3 mm

0.4 mm

• Journal wear:

Measure the journal diameter in two directions at

two places to obtain four readings on each journal

and check the journal bores with a bore gauge,

producing four readings on each. From these

readings, compute the radial clearance (Camshaft

journal clearance). If the service limit is exceeded

by any of the computed radial clearances, replace

the camshaft as necessary, cylinder head too.

JOURNALDIAMETER

26.007 mm to 26.02 mm

JOURNAL ANDCAMSHAFT CLEARANCE

STANDARDVALUE

LIMIT

0.027 to 0.053 mm

0.1 mm

Cylinder Head

De-carbon cylinder head:

Deposits of carbon will be found on its combustion

chamber surfaces and exhaust ports. Remember,

overheating tendency and loss of output are often due

to excessive carbon accumulation. De-carbon valves,

too.

NOTE

Do not use any sharp-edged tool to scrape off

carbon. Be careful not to scuff or nick metal

surfaces when decarbonizing. This applies to valves

and valve seats, too.

Distortion of gasketed surface:

Using a straightedge and thickness gauge, check the

flatness at a total of 6 locations.

If the limit, stated below, is exceeded, correct the

gasketed surface with a surface plate and abrasive

paper of about # 400 (waterproof silicon carbide

abrasive paper). Place the paper on and over the

surface plate and rub the gasketed surface against

the paper.